全文获取类型
收费全文 | 964篇 |
免费 | 99篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 296篇 |
金属工艺 | 6篇 |
机械仪表 | 18篇 |
建筑科学 | 28篇 |
矿业工程 | 3篇 |
能源动力 | 20篇 |
轻工业 | 402篇 |
水利工程 | 4篇 |
石油天然气 | 9篇 |
无线电 | 44篇 |
一般工业技术 | 115篇 |
冶金工业 | 41篇 |
原子能技术 | 3篇 |
自动化技术 | 71篇 |
出版年
2024年 | 1篇 |
2023年 | 10篇 |
2022年 | 19篇 |
2021年 | 45篇 |
2020年 | 21篇 |
2019年 | 48篇 |
2018年 | 44篇 |
2017年 | 40篇 |
2016年 | 40篇 |
2015年 | 36篇 |
2014年 | 55篇 |
2013年 | 65篇 |
2012年 | 83篇 |
2011年 | 91篇 |
2010年 | 55篇 |
2009年 | 56篇 |
2008年 | 56篇 |
2007年 | 56篇 |
2006年 | 53篇 |
2005年 | 31篇 |
2004年 | 19篇 |
2003年 | 24篇 |
2002年 | 22篇 |
2001年 | 15篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 16篇 |
1997年 | 13篇 |
1996年 | 9篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1991年 | 2篇 |
1988年 | 1篇 |
1986年 | 3篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1976年 | 8篇 |
1973年 | 3篇 |
1971年 | 1篇 |
排序方式: 共有1064条查询结果,搜索用时 31 毫秒
111.
The effect of polyphenols, phenolic acids and tannins (PPTs) from strawberry and apple on uptake and apical to basolateral transport of glucose was investigated using Caco‐2 intestinal cell monolayers. Substantial inhibition on both uptake and transport was observed by extracts from both strawberry and apple. Using sodium‐containing (glucose transporters SGLT1 and GLUT2 both active) and sodium‐free (only GLUT2 active) conditions, we show that the inhibition of GLUT2 was greater than that of SGLT1. The extracts were analyzed and some of the constituent PPTs were also tested. Quercetin‐3‐O‐rhamnoside (IC50=31 μM), phloridzin (IC50=146 μM), and 5‐caffeoylquinic acid (IC50=2570 μM) contributed 26, 52 and 12%, respectively, to the inhibitory activity of the apple extract, whereas pelargonidin‐3‐O‐glucoside (IC50=802 μM) contributed 26% to the total inhibition by the strawberry extract. For the strawberry extract, the inhibition of transport was non‐competitive based on kinetic analysis, whereas the inhibition of cellular uptake was a mixed‐type inhibition, with changes in both Vmax and apparent Km. The results in this assay show that some PPTs inhibit glucose transport from the intestinal lumen into cells and also the GLUT2‐facilitated exit on the basolateral side. 相似文献
112.
A rapid method for evaluation of the oxidation stability of castor oil FAME: influence of antioxidant type and concentration 总被引:1,自引:0,他引:1
Susana V. Araújo F. Murilo T. Luna Estlio M. Rola Jr. Diana C.S. Azevedo Clio L. Cavalcante Jr. 《Fuel Processing Technology》2009,90(10):1272-1277
The oxidation stability of castor oil fatty methyl ester (FAME), doped with four different phenolic antioxidants, was evaluated using a rapid method of thermal and air-contact degradation. The methodology is based on the induction times observed when the samples are contacted with pure oxygen at elevated pressures and temperatures. The results indicate different performances of the antioxidants as well as synergisms between antioxidants and biodiesel. In general, the addition of antioxidants increased from 6-15 times the stability of castor oil FAME., with BHA (butylated hydroxyanisol) showing the best results for improving antioxidation in castor oil biodiesel. 相似文献
113.
Marckmann CJ Andersen CE Aznar MC Bøtter-Jensen L 《Radiation protection dosimetry》2006,120(1-4):28-32
Optical fibre dosemeter systems based on radioluminescence and optically stimulated luminescence (OSL) from carbon-doped aluminium oxide (Al(2)O(3):C) crystals were developed for in vivo real-time dose rate and absorbed dose measurements in radiotherapy and mammography. A technique was also developed for making ultra-small dosemeter probes that can easily be placed inside patients in radiation treatment. These probes have shown excellent properties in both head and neck intensity-modulated radiation therapy treatment and in mammography. The dose-response of the OSL signal for the new optical fibre dosemeter system showed a repeatability within 0.15% at a dose level of 60 mGy when integrated over 100 s. The temperature dependence in the range 0-45 degrees C showed a reproducibility within 1.3% when the OSL signal was integrated over 100 s. 相似文献
114.
Mendiola JA Santoyo S Cifuentes A Reglero G Ibáñez E Señoráns FJ 《Journal of food protection》2008,71(10):2138-2143
The objective of this research was to evaluate the antimicrobial activity of carbon dioxide extracts of the unicellular biflagellated green alga Dunaliella salina against Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus niger. The effects of different extraction pressures ranging from 185 to 442 bar and extraction temperatures ranging from 9.8 to 45.2 degrees C on the extracts' composition and consequently on their antimicrobial activities were investigated. The extracts were analyzed by gas chromatography-mass spectrometry in order to identify the compounds responsible for the antimicrobial activity detected. Fourteen different volatile compounds and several fatty acids were identified. The highest antimicrobial activity was obtained using 314 bar and 9.8 degrees C. Under these conditions, the presence of an indolic derivative that had never been reported in D. salina was detected in the extract, together with polyunsaturated fatty acids and compounds related to carotene metabolism, such as beta-ionone and neophytadiene, with known antimicrobial activity. 相似文献
115.
Susana M Cardoso Isabel Mafra Ana Reis Dominique MR Georget Andrew C Smith Keith W Waldron Manuel A Coimbra 《Journal of the science of food and agriculture》2008,88(12):2079-2086
BACKGROUND: Thasos is an olive variety cultivated mainly in Greece used to produce ‘naturally black dry‐salted olives’. This process consists in placing the olives in disposed layers with coarse sodium chloride. The loss of water and other solutes gradually debitters and wrinkles the fruits. In this study, the effect of dry‐salt processing on the texture and cell wall polysaccharide composition was investigated. RESULTS: This type of processing affected primarily the mechanical properties of the olive flesh. In processed olives, this tissue was approximately 4.5 times stronger and also more deformable up to failure and stiffer than that from the raw olives. The dry‐salt processing had its strongest effect on pectic polysaccharides. This included the increment of solubilization of arabinose‐rich polymers in aqueous solutions, and thus their partial loss to the soak medium during dry‐salting. Contrarily, galacturonic acid‐rich polymers were further retained in the processed olives, probably by their stabilization within the cell walls by reduction of the electrostatic repulsion between the acidic groups of these polysaccharides due to sodium ions. CONCLUSION: The texture improvement of olive flesh by dry‐salt processing seems to be correlated with the reorganization of the galacturonic acid‐rich pectic polysaccharides into the cell wall of the fruit. Copyright © 2008 Society of Chemical Industry 相似文献
116.
Sántiz-Gómez Marco Antonio Mazorra-Manzano Miguel Angel Ramírez-Guerra Hugo Enrique Scheuren-Acevedo Susana María Navarro-García Gerardo Pacheco-Aguilar Ramón Ramírez-Suárez Juan Carlos 《Food science and biotechnology》2019,28(3):751-757
Food Science and Biotechnology - Chemical properties of fish gelatins differ from those of conventional mammalian sources, representing an attractive technological alternative for the food... 相似文献
117.
Bo Nan Susana Olhero Rui Pinho Paula M. Vilarinho Tim W. Button José M. F. Ferreira 《Journal of the American Ceramic Society》2019,102(6):3191-3203
Direct ink writing (DIW) has become a widespread additive manufacturing technique for material engineering, but its application in lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 piezoelectric ceramics from aqueous systems has not been reported so far to our knowledge. The main obstacle is the high extent of hydrolysis reactions undergone by the starting powders when dispersed in water, hindering the attainment of stable water-based colloidal suspensions. This paper reports on the preparation of stable aqueous inks from a deagglomerated and surface-treated powder synthesized by solid-state reaction and on DIW of macroporous lead-free piezoelectrics. Based on zeta potential and rheological measurements, the optimal amounts of processing additives (dispersant, binder, and coagulating agent) were selected to transform the initial fluid suspension to a viscoelastic paste with sufficient stiffness and stability for the printing process. Dielectric and piezoelectric properties of samples sintered under different temperatures were also investigated. 相似文献
118.
119.
120.